Safety timing control device of gas appliance

ABSTRACT

A safety timing control device is provided for a gas appliance and includes an electromagnetic switch, a first timing controller, a second timing controller, a power converter, and an alarm unit. The electromagnetic switch includes an electromagnet, a return spring, a housing, a connection bar, and a plug. The first timing controller sets a predetermined period of operation of the gas appliance in order to control the supply of electrical power to the electromagnet, which in turn opens or closes a gas passage of the gas appliance to prevent a potential risk of explosion caused by undesired continuous supply of fuel to a flaming site of the gas passage or to prevent a potential risk of being poisoned by carbon monoxide generated by incomplete combustion of fuel gas in the gas appliance.

FIELD OF THE INVENTION

The present invention relates to a safety timing control device of a gasappliance, and in particular to a safety timing control device of a gasappliance that uses an electromagnet to control a gas passage switch ofthe gas appliance.

BACKGROUND OF THE INVENTION

The progress of science and technology brings people the convenience ofenjoying various resources, including fuel, electricity, and water,among which fuel gas is an indispensable type of the resources formodern living of human beings. Appliances that are operated on fuel gas,such as gas ranges and water heaters, receive fuel gas that is suppliedthrough a piping system, allowing for easy and convenient use andoperation of the gas appliances.

Although the gas appliances provide convenience and easiness ofoperation and use, they also carry potential risks. For example, when auser, who is using a gas range, is unexpectedly interfered andabsent-mindedly leaves, totally forgetting the gas range is stillcooking food, dry-burning may occur if the cooking is not stopped andcontinuously lasts for an excessively long period of tine. This may leadto a risk of explosion or fire.

Further, water heaters are operated on natural gas as an energy source.People prefer to have windows and doors shut down in cold days and theymay unintentionally take a shower in an enclosed space. If the gas isnot completely combusted in the water heater and carbon monoxide isproduced and released, or the gas itself is released from the gas supplypassage, a potential risk that the user is poisoned may occur.

Thus, to provide a gas safety control device and a carbon monoxide andgas leakage detector is an issue that needs to be overcome urgently.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides a safety timingcontrol device of a gas appliance, which comprises a timer that countstime so that when the operation of the gas appliance extends for apredetermined period of time, a supply of electrical power to the safetytiming control device is cut off to block a gas passage of the gasappliance and thus cutting off the supply of fuel gas to a flaming siteof the gas appliance.

The present invention discloses a safety timing control device of a gasappliance, which comprises a first timing controller, a second timingcontroller, a power converter, an electromagnetic switch, and an alarmunit. The electromagnetic switch comprises an electromagnet, aconnection bar, a return spring, a housing, and a plug. The housing ismounted to an opening of a gas passage. The plug is received in the gaspassage. The connection bar has a first end extending through thehousing and coupled to a plug. The return spring is disposed around andencompasses the first end of the connection bar and is received in thehousing. The connection bar has a second end that is movable by amagnetic force generated by the electromagnet. The first timingcontroller is operable to count a predetermined time period of operationof the gas appliance and is electrically connected to an electricalpower supply unit. The second timing controller is electricallyconnected to the electromagnetic switch to count a time period ofconduction-on of the electromagnetic switch. The power converter iselectrically connected to the first timing controller and the secondtiming controller to convert and transfer electrical power supplied fromthe electrical power supply unit from the first timing controller to thesecond timing controller. The alarm unit is electrically connected tothe first timing controller so that when the predetermined time periodof operation of the gas appliance elapses, the first timing controllercontrols the alarm unit to issue an alarm signal. The electromagneticswitch is in a conduction-on condition during the predetermined timeperiod of operation and the electromagnet generates a magnetic forcethat overcomes a return spring force of the return spring to attract andmove the second end of the connection bar so as to open the gas passage.When the first timing controller reaches the predetermined time periodof operation, the first timing controller cuts off the electricalconnection with the electrical power supply unit to set theelectromagnetic switch in a cut-off condition, where the magnetic forceof the electromagnet varnishes and the plug is forced back by the returnspring force of the return spring to close the gas passage.

Further, the safety timing control device further comprises a carbonmonoxide and gas leakage detector, which is electrically connected tothe first timing controller so that when the carbon monoxide and gasleakage detector detects gas leaking outside the gas passage or carbonmonoxide generated by incomplete combustion of gas has a concentrationexceeding a threshold, an electrical signal is generated and applied tothe first timing controller to have the first timing controller cut offthe electrical connection with the electrical power supply unit andestablish a connection with the alarm unit to issue an alarm signal.

In summary, the present invention is applicable to general homeenvironment and comprises a timer interface that is easy to operate soas to help the elders or young children to conveniently, easily, andefficiently set a desired operation time of the gas appliance in orderto prevent potential risks caused by an undesired continuous supply offuel gas to a flaming site of the gas appliance and to prevent thepotential risk of poisoning caused by carbon monoxide generated throughincomplete combustion of fuel gas by the gas appliance.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art byreading the following description of preferred embodiments thereof withreference to the drawings, in which:

FIG. 1 is a schematic view illustrating a condition before electricalpower is supplied to a safety timing control device of a gas applianceaccording to the present invention;

FIG. 2 is a schematic view illustrating an initial condition of supplyof electrical power to the safety timing control device of the gasappliance according to the present invention;

FIG. 3 is a schematic view illustrating a condition of operation of thesafety timing control device of the gas appliance according to thepresent invention;

FIG. 4 is a schematic view illustrating a condition where the operationof the safety timing control device of the gas appliance according tothe present invention reaches a predetermined time period of operation;

FIG. 5 is a schematic view demonstrating an embodiment of a third timingcontroller of the safety timing control device of the gas applianceaccording to the present invention; and

FIGS. 6A and 6B are schematic views illustrating an operation of acarbon monoxide and gas leakage detector of the safety timing controldevice of the gas appliance according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings and in particular to to FIG. 1, aschematic view is given to illustrate a condition before electricalpower is supplied to a safety timing control device of a gas applianceaccording to the present invention. The safety timing control device 1of the gas appliance according to the present invention comprises afirst timing controller T1, a second timing controller T2, anelectromagnetic switch M, a power converter C, and an alarm unit B. Theelectromagnetic switch M comprises a plug M1, an electromagnet M2, areturn spring M3, a housing M4, and a connection bar M5. The housing M4is mounted to an opening formed in a gas passage G. The plug M1 isarranged in the gas passage G. The connection bar M5 has a first end M51that extends through the housing M4 and is coupled to the plug M1. Thereturn spring M3 is arranged around and encompasses the first end M51 ofthe connection bar M5 and is received and disposed in the housing M4.The connection bar M5 has a second end M52 that is movable by a magneticforce generated by the electromagnet M2. The first timing controller T1is operable to count a predetermined time period of operation of the gasappliance and is electrically connected to an electrical power supplyunit V. The second timing controller T2 is electrically connected to theelectromagnetic switch M to count a time period of conduction-on of theelectromagnetic switch M. The power converter C is electricallyconnected to the first timing controller T1 and the second timingcontroller T2 to convert and transfer the electrical power that issupplied from the electrical power supply unit V from the first timingcontroller T1 to the second timing controller T2. The alarm unit B iselectrically connected to the first timing controller T1 in such a waythat when the operation of the gas appliance reaches the predeterminedtime period, the first timing controller T1 controls the alarm unit B toissue an alarm signal.

The electromagnetic switch M is kept in a conduction-on condition withinthe predetermined time period of operation and the electromagnet M2generates a magnetic force that overcomes a return spring force of thereturn spring M3 to attract the second end M52 of the connection bar M5in such a way that the gas passage G is kept open. When the first timingcontroller T1 reaches the predetermined period of time of operation, thefirst timing controller T1 cuts off the electrical connection with theelectrical power supply unit V so that the electromagnetic switch M isput into a cut-off condition and the magnetic force of the electromagnetM2 varnishes so that the plug M1 is driven by the return spring force ofthe return spring M3 back to close the gas passage G. Further, theelectromagnet M2 comprises a recess formed therein so that when theelectromagnetic switch M is in the conduction-on condition, the magneticforce generated by the electromagnet M2 drives the connection bar M5 tomove, at least partly, into the recess and the plug M1 that is coupledto the connection bar M5 moves in unison therewith to open the gaspassage G; and when the electromagnetic switch M is in the cut-offcondition, the connection bar M5 is caused to move outward of the recessand the plug M1 of the connection bar M5 is moved in unison therewith toclose the gas passage G.

The safety timing control device 1 according to the present invention isapplicable to a gas appliance, such as a gas range and a water heater.When operating and using the gas appliance, a user may make a setting inadvance according to a desired time period of operation. F or example,when using the gas range to cook food, the user may first operate thefirst timing controller T1 to set an activation time period of the gasrange, meaning setting the time period of cooking food with the gasrange. Similarly, when the safety timing control device 1 is used with awater heater, the time period of operation of the water heater can beset according to the need of the user. In an embodiment of the presentinvention, the first timing controller T1 is provided with an interfacecomposed of a keypad of numeric buttons and allows for setting of timein a “stepless” manner with an available setting for the maximum timeperiod of operation being for example 90 minutes.

Referring to FIGS. 2-4, schematic views are given to respectivelyillustrate an initial condition of supply of electrical power to thesafety timing control device of the gas appliance according to thepresent invention, a condition of operation of the safety timing controldevice of the gas appliance according to the present invention, and acondition where the operation of the safety timing control device of thegas appliance according to the present invention reaches a predeterminedtime period of operation. The present invention uses the electromagnetM2, which when energized, generates a magnetic force, to control openingand closing of the gas passage G. The operation principle is that theelectromagnet M2 is not a permanent magnet and the electromagnet M2generates the magnetic force only when energized and loses the magneticforce when de-energized. Thus, with the first timing controller T1 ofthe safety timing control device 1 being electrically connected to theelectrical power supply unit V, the electromagnet M2 may selectivelygenerates a magnetic force that overcomes the return spring force of thereturn spring M3 to attract and move upward the connection bar M5. Sincethe first end M51 of the connection bar M5 is coupled to the plug M1,when the connection bar M5 is magnetically attracted and moved upwards,the plug M1 is moved in unison with the connection bar M5 and is alsoattracted upward thereby opening the gas passage G. When de-energized,the electromagnet M2 loses the magnetic force and the return springforce of the return spring M3 forces the plug M1 back a position ofclosing the gas passage G. The connection bar M5 is formed of orcomprises a magnetically attractable material in order to be attractedby the electromagnet M2 when the magnetic force is generated throughenergization. Further, in an embodiment of the present invention, theconnection bar M5 is arranged in a range of magnetic attraction of themagnetic force generated by the electromagnet M2 when it is energized sothat the connection bar M5 is magnetically attracted and movablethereby.

When the first timing controller Ti of the safety timing control device1 is activated and starts counting time, the electrical power suppliedfrom the electrical power supply unit V is converted and transferred bythe power converter C to the second timing controller T2 and is furthertransferred through the second timing controller T2 to the electromagnetM2 of the electromagnetic switch M. Then, the second timing controllerT2 counts the time period of conduction-on of the electromagnetic switchM and selection is made among windings according to the time period ofconduction-on. More specifically, the safety timing control device 1comprises a first winding L1 and a second winding L2, which are arrangedaround and encompass the electromagnet M2. The second timing controllerT2 establishes electrical connection with either the first winding L1 orthe second winding L2 according to the time when the electromagneticswitch M is energized. For example, in an embodiment of the presentinvention, in a time period of 2-3 seconds for conduction on, the secondtiming controller T2 is electrically connected to a circuit composed ofthe first winding L1 to supply a first electrical current I1 of 300 mA(I1 being illustrated in FIG. 2) to the electromagnet M2, so that arelatively large magnetic force is generated to overcome the returnspring force of the return spring M3. After a lapse of 2-3 seconds ofconduction on, since the electromagnet M2 has overcome the return springforce of the return spring M3, the second timing controller T2 cuts offthe connection thereof with the circuit of the first winding L1 andestablishes, instead, electrical connection with a circuit composed ofthe second winding L2 to supply a second electrical current I2 of 160 mA(I2 being illustrated in FIG. 3) to the electromagnet M2. In otherwords, the second electrical current I2 so supplied is less than thefirst electrical current I1, so that the electrical loading current ofthe safety timing control device 1 can be cut down by approximately 50%and this helps prevent burning out the winding through which theelectrical currently is continuously supplied for an excessively longperiod of time. Further, spring wire gauge and elastic module of thereturn spring M3 may be determined according to the magnitude of thefirst electrical current I1 in order to control the speed of the plug M1opening the gas passage G. In an embodiment of the present invention,the return spring M3 is made with a spring wire gauge being selected 0.6mm according to a first electrical current I1 of 300 mA.

Tanking the gas range as an example, reaching a predetermined time ofshutting down indicates the time period that is set for cooking food haselapsed and thus, automatic closing of the gas passage G of gas range isconducted to prevent a continuous supply of fuel gas to the gas rangethat might lead to an unexpected event of for example explosion.Similarly, when the operation and use of a water heater has reached apredetermined time period, indicating the use of the water heater by auser is completed, automatic closing of the gas passage G of the gasappliance is conducted to prevent potential risks that fuel gas has notbeen completely combusted and poisoning caused by carbon monoxide mayoccur.

It is noted here that the alarm unit B is electrically connected to theelectrical power supply unit V by the first timing controller T1. Inother words, when the first timing controller Ti has not reached thepredetermined period of time of operation, the alarm unit B is in anopen-circuiting condition with respect to the electrical power supplyunit V; and when the first timing controller T1 reaches thepredetermined period of time of operation, the alarm unit B iselectrically connected through the first timing controller T1 to theelectrical power supply unit V for being energized to generate an alarmsignal.

Further, referring to FIG. 5, a schematic view is given to demonstratean embodiment of a third timing controller of the safety timing controldevice of the gas appliance according to the present invention. Thesafety timing control device 1 according to the present invention mayfurther comprise a third timing controller T3, which counts a timeperiod of alarming by the alarm unit B and is electrically connected tothe first timing controller T1 and the alarm unit B. The time period ofalarming of the alarm unit B can be set to for example a period of 5-10seconds for informing a user that the gas passage G of the gas appliancehas been closed. When the gas appliance has reached the predeterminedperiod of time of operation, the first timing controller T1 switches theelectrical connection thereof to the third timing controller T3 so thatthe third timing controller T3 is electrically connected to theelectrical power supply unit V. When the time period of alarming of thealarm unit B elapses, the third timing controller T3 cuts off theelectrical connection between the alarm unit B and the first timingcontroller T1.

Further, in an embodiment of the present invention, the alarm unit Bcomprises a buzzer or an alarm light. The alarm sound may be of fixedintensity or the intensity is increased from a low level to a highlevel. The alarm light may comprise a lighting element, such as alight-emitting diode (LED). Further, in the present invention, the firsttiming controller T1, the second timing controller T2, and the thirdtiming controller T3 may be time relays.

Further, in addition to time counting of the predetermined time periodof operation of a gas appliance, the safety timing control device 1 ofthe present invention further provides a function of detecting leakageof fuel gas of the gas appliance or carbon monoxide generated byincomplete combustion of fuel gas. Referring collectively to FIGS. 6Aand 6B, schematic views are give to illustrate an operation of a carbonmonoxide and gas leakage detector of the safety timing control device ofthe gas appliance according to the present invention. A carbon monoxideand gas leakage detector S is electrically connected to the first timingcontroller T1 so that when the carbon monoxide and gas leakage detectorS detects fuel gas leaking outside the gas passage G or carbon monoxidegenerated by incomplete combustion of fuel gas has a concentration thatexceeds a predetermined threshold level, an electrical signal isgenerated and applied to the first timing controller T1 to have thefirst timing controller T1 cuts off the electrical connection with theelectrical power supply unit V so that the power converter C no longerconverts and transfers electrical power supplied from the electricalpower supply unit V through the first timing controller T1 to the secondtiming controller T2 and thus no electrical power is fed to theelectromagnet M2. Under such a condition that no electrical power is fedto the electromagnet M2, the magnetic force of the electromagnet M2varnishes and the spring return force of the return spring M3 causes theplug M1 n to move back to close the gas passage G, preventing undesiredcontinuous supply of fuel gas to a flaming site of the gas appliance.The first timing controller T1, when cutting off the electricalconnection of the electrical power supply unit V, is switched toconnection with the alarm unit B. In an embodiment of the presentinvention, the predetermined threshold level of the concentration ofcarbon monoxide or fuel gas can be standards stipulated in localregulations of each country or can be set by a user. Further, the carbonmonoxide and gas leakage detector S of the present invention iscombinable inside the safety timing control device or externally andelectrically connectable to the safety timing control device.

In an embodiment of the present invention, the electrical power supplyunit V supplies to the first timing controller T1 an alternatingcurrent, which is converted by the power converter C into a directcurrent fed to the second timing controller T2. The alternating currentthat is supplied from the electrical power supply unit V may be of anyvoltage levels supplied according to the local requirement. For example,to use the safety timing control device 1 of the present invention inTaiwan, the electrical power supply unit V receives and supplies analternating current of 110 volts and the power converter C convertingthe alternating current of 110 volts into a direct current of 12 voltsto be fed to the second timing controller T2. To use the safety timingcontrol device 1 of the present invention in the mainland of China, theelectrical power supply unit V receives and supplies an alternatingcurrent of 220 volts and the power converter C converting thealternating current of 220 volts into a direct current of 12 volts to befed to the second timing controller T2. Further, in an embodiment of thepresent invention, the power converter C comprises a device thatconverts electrical power, such as a transformer.

In summary, the present invention provides a safety timing controldevice of a gas appliance that is applicable to general home environmentand comprises a timer interface that is easy to operate so as to helpthe elders or young children to conveniently, easily, and efficientlyset a desired operation time of the gas appliance in order to preventpotential risks caused by an undesired continuous supply of fuel gas toa flaming site of the gas appliance and to prevent the potential risk ofpoisoning caused by carbon monoxide generated through incompletecombustion of fuel gas by the gas appliance.

Further, the safety timing control device of the gas appliance accordingto the present invention can be installed on all types and models of gasappliance, such as a water heater operated with natural gas or a gasrange operated with liquidized petroleum gas, all allowing for easyinstallation with only one gas hose fixed at a proper location on thegas appliance and connecting the gas hose to the safety timing controldevice and providing electrical connection with an electricity source toallow a proper and normal operation of the safety timing control device.During the operation of the safety timing control device, since theopening and closing of a gas passage of the gas appliance is onlyconducted with a timer, the original functionality of the gas applianceis generally not affected. Thus, the original way of operation of thegas appliance can be maintained. This allows the popularization of thesafety timing control device to be widened for applications in all sortsof gas appliance.

Although the present invention has been described with reference to thepreferred embodiments thereof, it is apparent to those skilled in theart that a variety of modifications and changes may be made withoutdeparting from the scope of the present invention which is intended tobe defined by the appended claims.

What is claimed is:
 1. A safety timing control device of a gasappliance, comprising: an electromagnetic switch, which comprises anelectromagnet, a connection bar, a return spring, a housing, and a plug,the housing being mounted to an opening of a gas passage, the plug beingreceived in the gas passage, the connection bar having a first endextending through the housing and coupled to a plug, the return springdisposed around and encompassing the first end of the connection bar andreceived in the housing, the connection bar having a second end that ismovable by a magnetic force generated by the electromagnet; a firsttiming controller, which is operable to count a predetermined timeperiod of operation of the gas appliance and is electrically connectedto an electrical power supply unit; a second timing controller, which iselectrically connected to the electromagnetic switch to count a timeperiod of conduction-on of the electromagnetic switch; a powerconverter, which is electrically connected to the first timingcontroller and the second timing controller to convert and transferelectrical power supplied from the electrical power supply unit from thefirst timing controller to the second timing controller; and an alarmunit, which is electrically connected to the first timing controller sothat when the predetermined time period of operation of the gasappliance elapses, the first timing controller controls the alarm unitto issue an alarm signal; wherein the electromagnetic switch is in aconduction-on condition during the predetermined time period ofoperation and the electromagnet generates a magnetic force thatovercomes a return spring force of the return spring to attract and movethe second end of the connection bar so as to open the gas passage; andwhen the first timing controller reaches the predetermined time periodof operation, the first timing controller cuts off the electricalconnection with the electrical power supply unit to set theelectromagnetic switch in a cut-off condition, where the magnetic forceof the electromagnet varnishes and the plug is forced back by the returnspring force of the return spring to close the gas passage.
 2. Thesafety timing control device as claimed in claim 1, wherein theconnection bar comprises a material that is magnetically attractable. 3.The safety timing control device as claimed in claim 1 furthercomprising a first winding and a second winding wound around andencompassing the electromagnet, the second timing controller beingelectrically connectable to the first winding or the second windingaccording to a time of conduction-on of the electromagnetic switch,wherein during a time period of conduction-on of 3 seconds for theelectromagnetic switch, the second timing controller is electricallyconnected to the first winding and after time lapse of 3 seconds ofconduction-on time of the electromagnetic switch, the second timingcontroller is electrically connected to the second winding.
 4. Thesafety timing control device as claimed in claim 3, wherein a firstelectrical current flowing through the first winding is greater than asecond electrical current flowing through the second winding.
 5. Thesafety timing control device as claimed in claim 1 further comprising athird timing controller, which counts an alarm time period of the alarmsignal and is electrically connected to the first timing controller andthe alarm unit.
 6. The safety timing control device as claimed in claim1, wherein the electrical power supply unit supplies to the first timingcontroller an alternating current, which is converted by the powerconverter into a direct current to be fed to the second timingcontroller.
 7. The safety timing control device as claimed in claim 1,wherein the power converter comprises a transformer.
 8. The safetytiming control device as claimed in claim 1, wherein the alarm unitcomprises a buzzer or an alarm light.
 9. The safety timing controldevice as claimed in claim 1 further comprising a carbon monoxide andgas leakage detector, which is electrically connected to the firsttiming controller so that when the carbon monoxide and gas leakagedetector detects gas leaking outside the gas passage or carbon monoxidegenerated by incomplete combustion of gas has a concentration exceedinga threshold, an electrical signal is generated and applied to the firsttiming controller to have the first timing controller cut off theelectrical connection with the electrical power supply unit andestablish a connection with the alarm unit.
 10. The safety timingcontrol device as claimed in claim 5, wherein the first timingcontroller, the second timing controller and the third timing controllerare time relays.